1. Field of the Invention
This invention relates to a sheet receiving device for use in an image forming apparatus such as a copying apparatus or a facsimile apparatus, and more particularly to a sheet receiving device for receiving sheets discharged from an image forming apparatus.
2. Related Background Art
A sheet receiving device for recording sheets having images already formed thereon which is installed on a facsimile apparatus, a copying apparatus or the like is usually provided in a projected form as a recording sheet receiving tray on the apparatus body. An example of the facsimile apparatus provided with such a recording sheet receiving tray is shown in FIG. 2 of the accompanying drawings.
In FIG. 2, the reference numeral 1 designates a facsimile apparatus body provided with an information reading and transmitting system for reading the information of an original 3 fed on an original supporting table 2 by a reading unit 4 designed to convert said information into an electrical signal by a photoelectic conversion element 4c such as a CCD through the intermediary of mirrors 4a and 4b and transmitting said information, and an information receiving and recording system having a recording head 8 for recording the received information on a recording sheet 7 paid away from a recording paper roll 5 by a platen roller 6.
In FIG. 2, an original receiving tray 9 for receiving the original 3 fed out from the original supporting table 2 is provided on the left-hand side of the facsimile apparatus body 1, and a recording sheet receiving tray 11 for receiving a recording sheet 7 having an image already formed thereon by the recording head 8 and cut into a predetermined length by a cutter 10 is projectedly provided on the right-hand side of the facsimile apparatus body 1. The reference numeral 12 denotes a power source unit including a power source device, etc.
In recording apparatuses such as facsimile apparatuses, compactness and light weight thereof are strongly required. However, in the aforedescribed recording apparatus, the original receiving tray 9 and the recording sheet receiving tray 11 are projected on the opposite sides of the facsimile apparatus body 1 and therefore, even if the apparatus body 1 is made compact, these projected trays prevent the actual installment space from being made very small.
As a means for solving this problem, it would be conceivable to arrange the trays on one side of the apparatus body and thereby to omit the space for one tray. However, if the trays are concentrated on one side of the apparatus body, the drive systems for the information reading and transmitting system and the information receiving and recording system will also be concentrated on that side and as a result, the space efficiency of the interior of the apparatus will be hindered and the drive systems will be complicated. This may lead to reduced reliability, and further to increased costs.
Also, in the aforedescribed prior-art recording apparatus, recording sheets having images already formed thereon are discharged from the apparatus with their recording surfaces facing upward and are successively piled. Thus, when a plurality of pages of originals are to be recorded, recording sheets having images already formed thereon which are discharged from the apparatus are piled with the first page lying at the bottom and the second and subsequent pages successively lying thereon, and this order of piling is converse to the order of the originals. Therefore, after the completion of the recording operation, it is necessary to rearrange the recording sheets having images already formed thereon in the order from the first page, and this is a very time-consuming work.
Further, a sheet wound into the form of a roll such as a recording sheet used in a facsimile apparatus or the like has a strong curl and is difficult to receive in good order on a straight tray surface as is conventional. Recently, there is the tendency to make the outer diameter of the roll as small as possible without changing the length of the sheet, in conformity with the compactness of the apparatus body, and as a means therefor, there is adopted a method of making the winding core small in diameter. As a result, the curl becomes more remarkable and the development of a method of receiving recording sheets after image formation which will well cope therewith is desired.
So, to solve these problems, the applicant invented and proposed a recording sheet receiving tray as shown in FIG. 3 of the acompanying drawings (U.S. Pat. No. 4,768,063).
In FIG. 3, a recording sheet receiving tray 13 is provided below and near the recording sheet outlet of a facsimile apparatus 1, and this tray is constituted by an outer tray 14 as a first guide member against which a recording sheet 7 after having an image already formed thereon bears and which guides this recording sheet downwardly, and an inner tray 15 as a second guide member for forming a recording sheet receiving space 16 in opposed relationship with the outer tray 14.
The lower end portion of the outer tray 14 is connected to the lower end portion of the inner tray 15 by a pin 17, and the outer tray 14 is pivotally supported about the pin 17. The outer tray 14 is restrained relative to the apparatus body 1 by a click mechanism, not shown, and is normally held in its closed position.
The outer tray 14 is provided with a plurality of ribs 18 so that the contact resistance thereof with the leading end edge of the recording sheet 7 may be reduced and the recording sheet may be smoothly guided to the receiving space 16 of the recording sheet receiving tray 13. Also, a v-shaped gripping portion for gripping the leading end edge of the recording sheet 7 is formed by the outer tray 14 and the inner tray 15. Further, at the upper end of the outer tray 14 in its closed position, an open portion 20 is provided so that the trailing end edge of the recording sheet 7 can be reversed in the form of a loop and the recording sheet can be discharged outwardly when a long recording sheet 7 is received.
However, the force with which the V-shaped gripping portion 19 grips the leading end edge of the recording sheet 7 has been limited, and such tray has been unsuitable for receiving a number of recording sheets. Further, during the reception of a remarkably long recording sheet, there has been the problem that the sheet slips down from the tray.
So, to solve these problems, Applicant proposes in Japanese Patent Application Laid-Open No. 63-218463 a recording sheet contraction tray as shown in FIG. 4 of the accompanying drawings.
This solving means is characterized by the provision of a first guide member 14 for downwardly guiding the leading end edge of a recording sheet having an image recorded thereon by a recording unit, a second guide member 15 for forming a recording sheet receiving space in opposed relationship with said first guide member, an open portion 20 at the upper end of said first guide member for permitting the reversal of the trailing end edge of the recording sheet, a pair of discharge rollers comprising a discharge roller 28 provided on the recording sheet discharge portion side of the recording apparatus and driven and a pinch roller 29 provided in opposed relationship with said discharge roller, a rotatable grip roller 33 provided in said receiving space, and a pressing plate 30 provided in said receiving space for gripping the leading end edge of the recording sheet fed downwardly.
Thus, when the recording sheet discharged from the image forming unit of the recording apparatus is to be received onto the recording sheet receiving tray, the recording sheet having an image already formed thereon which is paid away from the pair of discharge rollers 28 and 29 in the discharge portion has its leading end edge bearing against the first guide member 14 and is guided downwardly into the receiving space for the recording sheet.
The leading end edge of the recording sheet which has come into the sheet receiving space is caught by the grip roller 33 and fed downwardly and gripped by a gripping portion, whereafter it bears against the bottom of the tray and its forward movement is stopped.
When image recording is going on, the recording sheet still continues to be discharged, and is discharged in the form of a loop from the apparatus body by the rotation of the pair of discharge rollers. On the other hand, when image recording is completed and the recording sheet is cut by a cutter, the trailing end portion of the recording sheet hangs down outside the apparatus body by its gravity. Since at this time, the leading end edge of the recording sheet is gripped or nipped by the gripping portion, the recording sheet will never slip down from the apparatus body.
However, the gap between the outer tray 14 and the grip roller 33 or the outer tray and the pressing plate 30 for gripping the recording sheet 7 is of a certain predetermined value, and as a matter of course, the number of recording sheets 7 gripped has been limited.